RFR: 8308869: C2: use profile data in subtype checks when profile has more than one class [v8]

[Roland Westrelin]

On Fri, 14 Jul 2023 21:34:17 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - never common SubTypeCheckNode nodes
>>  - keep both ways of doing profile
>
> test/hotspot/jtreg/compiler/c2/irTests/ProfileAtTypeCheck.java line 47:
> 
>> 45:         }
>> 46:         flags.add("-XX:+IgnoreUnrecognizedVMOptions");
>> 47:         flags.add("-XX:+UseParallelGC");
> 
> The test fails when another GC is specified externally.

Should be fixed in the new commit. I also improved the test a bit (added one test case with array store checks, duplicated the rules so there's no need to run with -XX:-UseCompressedClassPointers, run tests with only c1 profile collection and only interpreter profile collection to exercise new profile collection code paths independently).

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PR Review Comment: https://git.openjdk.org/jdk/pull/14375#discussion_r1268077722